Vacuum fuel-feed system



y 14, J. c. COULOMBE VACUUM FUEL FEED SYSTEM Filed Jul y "19, 1923 INVENTOR. BYW

ATTORNEY. v

Patented May 14, 1929..

JOSEPH C. COULOMBE, J3 KOKOMO, INDIANA.

VACUUM FUEL-FEED SYSTEM.

Application filed July 19,

The purpose of this invention is to-provide an improved. device for sluoplying liquid fuel to an internal combustion engine by means of suction, now generally known as vacuum fuel feed systems.

It is sometimes desirable to have a device of this character whereby the suction is shut off, excepting during the interval that fuel is being drawn from the main tank, it is. in this respect that the 1nvent1on hercinatter.

described differs from my Patents lilo. 1,365,15al, issued Jan. 11, 1921, and No. 1,424,715, issued Aug. 1, 1922.

The device hereinafter described and shown in the drawings comprises the essentials of a vacuum feed system. The engine, gasoline tank forming the source of supply, and the connection of the source of suction (engine manifold or pump) are not illustrated. These parts are now well known in the art.

Referring to the d 'awings, Fig. 1is a vertical sectional View through lines XE-Y 'of Fig. 2, and Figure 2 is a plan view of the top of the device.

An outside shell 1 forms a reservoir 2, below the casing of the inner aerating chamber 8., A block 4- is securely fastened to the top of the casing of the chauiber 3 by means of the hollow cap screws 5 and 6, in which are respectively located the atmos-i pheric air inlet valve 7, and the suction con-. necticm valve 8. 9' is for a connection leading to a source of suction, 10 is the fuel inlet connection, 11 is the fuel outlet connection to the carlniretter, 12 is a drain valve. The bottom plate 13 of chaniibcr 3 has a suspended tube 14: which forms the fuel outlet from the operating chamber 3, to the chamber 2, which outlet is controlled by a compound valve of which 15 is the primary valve and 16 the secondary valve, guided by strap 17. A valve link 18 is threaded through valve 153 to allow for initial adj ustment. A valve lever 19 is pivotally secured as at 23, to plate 13 through a support 12", stud 12*, and. nut 12 and is operated by a float 20. An inverted cup 21 is mounted above 1'loat20 and secured to theyfloat rod 22 so that valve 8, rod 22, float and cup 21 move asa unit and are held to plate 13 by means of fulcrum pin 23 and removable with plate 13 when the screws 2% are removed. An annular flange 25 at the lower end of chamber 3 supports plate 13 and is tapped. to receive screws 24. A resilient 1923. Serial No. 652,544.

gasket 26 is interposed tov produce a tight oint. A cup-shaped portion 27 indented in the top of chamber 3 for ease of priming, from the bottom of this cup-shaped portioh 27 leads a pipe 28 which runs through chamher 3 and is soldered in flange 25, extending through plate 13 so that whatever fuel is placed in priming cup 27 will run direct to chamber 2. A. dust cover 29 is hold in place by wire 30.

The inverted cup 21, which forms a part of float 20, is so located on the float that the normal buoyancy point of the float unit indicated by the dot as Fig. 1 will be below the lower eiilge of the inverted cup 21, that to say, when the liquid within the operating chamber 8 rises to a level a little below the lower edge of the cup the upward pressure of the body of liquid then displaced by the float unit will be equal to the weight of the float unit, tl e advantages of which will be presently pointed out. Inasmuch as the lower edge of the cup 21 will sometimes be immersed. in the liquid fuel, during high suction periods on the filling cycle, it is essential that the level of fuel must get below the cup 21. during the dumping cycle so as to replenish the air in said cup 21.

The positiveness of operation of the device is entirely dependent on the proportion of the valves, float, and the distance of float travel. During low suction periods the pri' mary valve 13, which is opened by the lloat against suction, must be of sul'licientarea to resist the opening action of the float to such an extent that the floatunit will become in1- mersed above its normal point of buoyancy as indicated by the the dotted line X Fig. 1 sufficiently to allow the float to travel upwards to bring the suction valve 8 against its seat when valve 15 lets go. During low suction periods the suction valve 8 must be of suflicient area to resist the opening action of the float to such an extent that the liquid level must drop sufiiciently below the normal buoyancy point of the float unit so that when valve 8 lets go the float will travel down and close valves 15 and 16. During high suction periods the float unit must havh suflicient buoyancy to open valve 15 before it becomes completely immersed. During high suction periods the float unit must also have suflicient weight to pull valve 8 from its seat before the liquid level drops entirely below the float unit.

Atmosphere valve 7 is held to its seat by suction during the filling cycle and extends through its seat so that it may be held off its seat by the float while the suction valve 8 is on its seat. The resistance of atmosphere valve 7 against opening should be less than the resistance of valve 15, it must however be sufficiently large to admit atmospheric air fast enough to not impede the flow of fuel from chamber 3 to 2, even if the suction valve 8 does not seat tightly, as will generally happen through wear or imperfectness in manufacture.

Atmosphere is admitted constantly to the lower chamber 2 by the loose fit of chamber 3 in shell 1.

The fitting 6 has a chamber 31 to assist in assembling.

The operation of the device is as follows:

The parts being in the position shown, suction will be produced in chamber 3, draw ing fuel from the main reservoir, the fuel level will rise partly immersing the float. \Vhen the float becomes immersed sufiiciently to attain enough buoyancy to force primary valve 15 from its seat, suction will be reduced sufliciently to allow air inlet valve '7 to open, thereby allowing valve 16 to open and valve 8 to close. The fuel will then flow by gravity from chamber 3 to 2. As the :fuel level lowers below the normal buoyancy point of the float, the float will be partly sustained by the suction on valve 8, when the level has dropped sufficiently below the normal buoyancy point of the float to overcome the suction pull on valve 8, the float will drop to its lowest position closing valves 15 and 16 and allowing valve 7 to drop to its seat,when the operation will be repeated.

' I claim 1. In a vacuum fuel feed system, an operating chamber having a fuel inlet, fuel outlet and an air outlet, a valve controlling said fuel outlet held'to its'seat by the reduced pressure in the operatingchamber, a valve controlling said air outlet, and a float in said chamber connected to each of said valves to positively move said valves during any movement of the float, the valve that controls the fuel outlet, and the float, being proportioned to each other, as described, so that the valve is held'to its seat, by the reduccd pressure in the operating chamber, until the float is immersed beyond its normal buoyancy level. v

2. Thecombination stated in claim 1, in cluding also an air inlet and a float-operated valve controlling the air' inlet.

'3. The combination stated in claim 1, including also an air inlet and a float-operated valve controlling the air inlet, the fuel out let valve being disposed to open outwardly I and the said air inlet valve being float-opera'ted only on the opening movement of the outlet valve.

4. Ina vacuum fuel feed system, an operating chamber having a fuel inlet, a fuel outlet, and an air outlet to a suction line; float operated valves for said air outlet and said fuel outlet, and a float positively connected to said valves and imparting its every movement thereto, the valve that controls the air outlet, and the float, being propon tioned to each other, as described, so that the valve is held to its seat, by the reduced pressure in the suction line, until the liquid level falls below the normal buoyancy level of the float unit.

5. In a vacuum fuel feed system, an operating chamber having a fuel inlet, a fuel out-let and an air outlet; float operated valves for said air outlet and said fuel outlet, the valve for the fuel outlet being held to its seat by the reduced pressure in the operating chamber, and a float positively connected to said valves and imparting movement thereto upon every movement of the float, the valve controlling the fuel outlet and the float being PI'OlJOllllOllCd to each other, as described, so that the valve is held to its seat, by the reduced pressure in the operating chamber, until the float is immersed beyond its normal buoyancy level, but is rclsascd from its seat by the float before complete immersion. of the latter.

6. In a vacuum fuel feed system, an operating chamber having a fuel inlet, a fuel outlet, and an air outlet to a suction line, a valve for controlling the fuel outlet held to its seat by the reduced pressure in the operating chamber, a valve for controlling the air outlet held to its seat by the reduced pressure in the suction line, and a float positively connected to the said valves and imparting movement thereto upon every movement of the float, the said valves and the said float being proportioned to each other as described, so that the valve of the fuel outlet is held to its seat, by the reduced pressure in the operating chamber, until the float is immersed beyond its normal buoyancy level and the float has suflicient lifting power to unseat the valve controlling the air outlet before the liquid level drops entirely below the float.

7. In a vacuum fuel feed system, an operating chamber adapted to have intermittent periods of atmospheric and subalmospheric pressure therein, and a float unit controlling the pressures within the said chan1- ber, comprising a float and an inverted cup rigidly connected with each other so that they move as a unit, the float unit being constructed so that the liquid level within the operating chamber when the float unit becomes buoyant or begins to float is below the lower open end of the inverted cup, thus permitting the buoyancy of the float to be rapidly increased by the filling of the chamber with liquid above the said level.

8. A vacuum fuel feed system having a fuel inlet and a fuel outlet and a suction connection, a float unit for controlling the flow of fuel through the system, said unit comprising a main float member and an in verted cup secured thereto, said cup located with its lower edge above the normal buoyancy point of the float unit.

9. In a vacuum fuel feeding system, a float unit for controlling said system comprising a buoyant body and inverted cup secured thereto, said cup having its lower edge mounted above the normal buoyancy point of the float unit.

10. In a device of the character described, an operating chamber having a suction connection, a fluid connection and discharge connection, a compound valve controlling the discharge connection, a composite float having a body part and a fluid containing part permanently attached thereto, to increase the total buoyancy of the float and operative connections between the float and compound valve actuating the latter upon movements of the former.

11. In a device of the character described having an operating chamber, a composite float for controlling the operation of said chamber, said float including a buoyant body section and an inverted cup permanently secured to and moving therewith and forming an air chamber, said air chamber open at its lower edge to the control chamber.

12. I11 a device of the character described having an operating chamber, a float for controlling the operation of said chamber, said float being of composite form and having a main buoyant body part and an in vcrted cup secured thereto and providing an air chamber, the lower edge of said cup being open to the operating chamber and adapted to permit compression of air Within the chamber upon a rise of fluid in the operating chamber.

In testimony whereof, I have hereunto set my hand at Kokomo, Indiana, this 17th day of July, 1923.

JOSEPH C. COULOMBE. 

